Intel DG41MJ: Affordable 775 Mini-ITX

Lower cost boards ship with simple heatsinks on the Northbridge and Southbridge
while those targeted at enthusiasts typically have large heatpipe coolers and
heatsinks on the voltage regulation modules near the CPU socket. A well-cooled
motherboard can deliver better power efficiency and stability. To test cooling,
reduced the CPU fan speed to 5V, and stressed the CPU and GPU for 10~20 minutes.
Temperatures were recorded with a spot thermometer (hottest point).

Heatsink Temperatures

Measuring Point

DG41MJ

DG45FC

SB Chip

68°C

72°C

NB Heatsink

48°C

71°C

Ambient temperature: 22°C

On load, the DG41MJ's Northbridge heatsink measured much lower than the DG45FC.
The Southbridge, which is bare on both boards, registered a few degrees lower
as well. Overall, cooling is not an issue for the board.

SpeedFan Support

For Windows users, SpeedFan is our application of choice for fan control. It
can be configured to raise or lower multiple fan speeds to designated limits
when any specified temperature threshold is breached.

SpeedFan main screen.

Like many Intel boards, the current version of SpeedFan was not compatible.
It did not show fan speeds or offer any fan controls.

BIOS Fan Control

To test the board's fan control, we connected the CPU fan to a manual fan speed
controller so we could slow it down to induce higher CPU temperatures during
load. A Scythe Kama 92mm PWM fan (2500 RPM maximum) was connected to the CPU
fan header and a Scythe Kama 80mm fan (1500 RPM maximum) was connected to the
system fan header. Fan speeds were measured manually with a tachometer. In the
BIOS, "Lowest System Fan Speed" was set to "Slow."

Heatsink Temperatures

Criterion

CPU Fan (2500 RPM)

System Fan (1500 RPM)

Min. Fan Speed

560 RPM

720 RPM

Trigger Temp.

50°C

65°C

Range

Unknown, 1210 RPM @ 75°C

Unknown, 1320 RPM @ 75°C

Ambient temperature: 22°C

The CPU and System fans spun at 560 and 720 RPM respectively with the system
idle. The CPU fan did not increase in speed until the Core temperature reached
50°C, while the System fan followed suit at around 65°C. We were unable
to determine the temperature range because both fans failed to reach their maximum
speeds by the time the Core temperature hit 75°C (which was accomplished
by turning off the actual CPU fan for several minutes). We were not comfortable
stressing the processor further and ended the test.

Surprisingly Intel's fan control on this particular board was too passive,
waiting for too long before ramping up the fans, and even then the rate of increase
was not aggressive enough for our liking.